Abstract

The annual net primary production (ANPP) of temperate grasslands and production of livestock industriesis predicted to decrease in southern Australia with future climate change. By using biophysicalmodelling, we address productivity and profitability of grazing systems while considering systemic combinationof grassland management and animal genetic improvement options. Single incremental adaptationswill not completely avert declines in productivity and profitability; hence, combinations of adaptationsare needed. The synergistic effects of these adaptations could potentially offset decreasing productionand profit in 2030 over the majority of southern Australia, but not in some drier regions after 2030. Theseresults demonstrate the need for changes in strategies over time with greater complexity of adaptationsin drier regions. Upscaling over all southern Australia, financially optimal systemic combination(fully enhanced systems) could increase profit by 68.61%, 68.63% and 50.81% in 2030, 2050, and 2070,compared to the production of the historical period with current farm system management. Financiallymotivatedchanges to grazing systems will result in improvement in grassland health, soil environment,and water use efficiency. However, full adaption of systemic adaptation will lead to greater ruminant CH4emission from 70 kg ha−1 yr−1 in baseline (1970–1999) to 84, 83, and 75 kg ha−1 yr−1 in 2030, 2050, and2070. Higher rates of CH4 emissions may affect profitability depending on future emissions pricing. Inmost of the drier regions, greater input intensity and management complexity may be required whichrequirement is likely to increase over time. However some of the drier regions would still require transformativeadaptations.